Wen-Chao Liu, Liang Wen, Tao Xie, Hao Wang, Jiang-Biao Gong and Xiao-Feng Yang
Erythropoietin (EPO) exerts a neuroprotective effect in animal models of traumatic brain injury (TBI). However, its effectiveness in human patients with TBI is unclear. In this study, the authors conducted the first meta-analysis to assess the effectiveness and safety of EPO in patients with TBI.
In December 2015, a systematic search was performed of PubMed, Web of Science, MEDLINE, Embase, the Cochrane Library databases, and Google Scholar. Only English-language publications of randomized controlled trials (RCTs) using EPO in patients with TBI were selected for analysis. The assessed outcomes included mortality, favorable neurological outcome, hospital stay, and associated adverse effects. Continuous variables were presented as mean difference (MD) with a 95% confidence interval (CI). Dichotomous variables were presented as risk ratio (RR) or risk difference (RD) with a 95% CI. Statistical heterogeneity was examined using both I2 and chi-square tests.
Of the 346 studies identified in the search, 5 RCTs involving 915 patients met the inclusion criteria. The overall results demonstrated that EPO significantly reduced mortality (RR 0.69, 95% CI 0.49–0.96, p = 0.03) and shortened the hospitalization time (MD −7.59, 95% CI −9.71 to −5.46, p < 0.0001) for patients with TBI. Pooled results of favorable outcome (RR 1.00, 95% CI 0.88–1.15, p = 0.97) and deep vein thrombosis (DVT; RD 0.00, 95% CI −0.05 to 0.05, p = 1.00) did not show a significant difference.
The authors suggested that EPO is beneficial for patients with TBI in terms of reducing mortality and shortening hospitalization time without increasing the risk of DVT. However, its effect on improving favorable neurological outcomes did not reach statistical significance. Therefore, more well-designed RCTs are necessary to ascertain the optimum dosage and time window of EPO treatment for patients with TBI.
Cheng-Siu Chang, Chun-Chao Chuang, Ming-Fan Wu, Wen-Shan Liu, Hsien-Tang Tu and Chuan-Fu Huang
Most cases of tumor-related hemifacial spasm (HFS) are treated by open surgery. The authors report the effects of Gamma Knife surgery (GKS) on benign tumor–related HFS at a mean follow-up time of 84 months.
Between 2000 and 2011, 6 patients (5 women and 1 man) harboring single tumors of the cerebellopontine angle (4 meningiomas and 2 vestibular schwannomas [VSs]) and experiencing HFS underwent GKS as a primary treatment. The mean age of the patients at the time of radiosurgery was 52.7 years (range 45–60 years).
The patients' tumors lay within the radiosurgical target area. In the 4 cases of meningioma, the mean radiosurgical treatment volume was 5.3 cm3 (range 1.2–9.6 cm3), and the mean radiosurgical tumor margin dose was 14.1 Gy (range 12–18 Gy); in the 2 cases of VS, the treatment volume was 2.5 cm3 in 1 patient and 11.2 cm3 in the other, and the margin doses were 11.5 and 12 Gy, respectively. The mean duration of HFS symptoms was 15.5 months (range 3–36 months).
The mean follow-up period was 84 months (range 40–110 months). Overall, 4 (66%) of the 6 patients experienced complete relief from HFS without medication after GKS and 1 patient obtained a good outcome. The mean time for improvement to be realized was 12.6 months (range 3–24 months). Only 1 patient failed to experience relief from HFS, and coincidentally, the tumor did not shrink in that case. In all 6 patients (100%), tumor growth was controlled at a mean follow-up of 56 months after GKS: in 5 patients the tumor had decreased in size and in the other patient the tumor size remained unchanged. No new neurological deficit was noted after GKS, and 1 patient with facial numbness reported improvement after tumor shrinkage.
Gamma Knife surgery appears to be effective in treating benign tumor–related HFS and in controlling tumor growth. A reduction in tumor volume is related to spasm improvement. Although a time latency for spasm relief is associated with GKS, minimal side effects are expected.
Chuan-Fu Huang, Shyh-Ying Chiou, Ming-Fang Wu, Hsien-Tang Tu, Wen-Shan Liu and Jim-Chao Chuang
Cellular density is a major factor for change in the apparent diffusion coefficient (ADC). The authors hypothesized that loss of tumor cells after Gamma Knife surgery (GKS) may alter the ADC value and used diffusion weighted MR imaging (DW imaging) to evaluate cellular changes in brain tumors to detect their treatment response and the efficacy of GKS.
In this paper the authors describe a prospective trial involving 86 patients harboring 38 solid or predominantly solid brain metastases, 30 meningiomas, and 24 acoustic neuromas that were treated by GKS. The patients underwent serial MR imaging examinations, including DW imaging, before treatment and at multiple intervals following GKS. Follow-up MR images and clinical outcomes were reviewed at 3-month intervals for metastatic lesions and at 6-month intervals for benign tumors. Apparent diffusion coefficients were calculated from echoplanar DW images, and mean ADC values were compared at each follow-up.
The mean ADC value for all meningiomas was 0.82 ± 0.15 × 10−3 mm2/sec before GKS. The mean ADC value as of the last mean follow-up of 42 months was 1.36 ± 0.19 × 10−3 mm2/sec, a significant increase compared to that before treatment (p < 0.0001). Calcification (p = 0.006) and tumor recurrence (p = 0.025) significantly prevented a rise in the ADC level.
The mean ADC value for all solid acoustic neuromas was 1.06 ± 0.17 × 10−3 mm2/sec before GKS. The mean ADC value as of the last mean follow-up of 36 months was 1.72 ± 0.26 × 10−3 mm2/sec, a significant increase (p = 0.0002) compared with values before GKS. At the last mean MR imaging follow-up there appeared to be tumor enlargement in 3 patients (12.5%); however, since the ADC values in these patients were significantly higher than the preradiosurgery values, the finding was considered to be a sign of radiation necrosis rather than tumor recurrence.
The mean ADC value of metastatic tumors was 1.05 ± 0.12 × 10−3 mm2/sec before GKS. This value rose significantly (p < 0.0001) to 1.64 ± 0.18 × 10−3 mm2/sec after GKS at a mean follow-up of 9.4 months. Magnetic resonance imaging showed that 89% of these tumors had been controlled by GKS. In 2 patients there were enlarged lesions, but the ADC values were the same as pre-GKS levels, and therefore, the lesions were deemed recurrent.
Apparent diffusion coefficient values may be useful in evaluating treatment results before a definitive change in volume is evident on imaging studies. In some patients in whom imaging findings are equivocal, ADC values may also be used to distinguish radiation-induced necrosis from tumor recurrence.
Chia-An Wu, Huai-Che Yang, Yong-Sin Hu, Hsiu-Mei Wu, Chung-Jung Lin, Chao-Bao Luo, Wan-Yuo Guo, Cheng-Chia Lee, Kang-Du Liu and Wen-Yuh Chung
Gamma Knife surgery (GKS) obliterates 65%–87% of cavernous sinus dural arteriovenous fistulas (CSDAVFs). However, the hemodynamic effect on GKS outcomes is relatively unknown. The authors thus used the classification scheme developed by Suh et al. to explore this effect.
The authors retrospectively (1993–2016) included 123 patients with CSDAVFs who received GKS alone at the institute and classified them as proliferative type (PT; n = 23), restrictive type (RT; n = 61), or late restrictive type (LRT; n = 39) after analyzing their pre-GKS angiography images. Treatment parameters, the presence of numerous arterial feeders, and venous drainage numbers were compared across the CSDAVF types. Patients’ follow-up MR images were evaluated for the presence of complete obliteration. A Kaplan-Meier analysis was conducted to determine the correlation between CSDAVF types and outcomes.
The 36-month probability of complete obliteration was 74.3% for all patients, with no significant differences across types (p = 0.56). PT had the largest radiation volume (6.5 cm3, p < 0.001), the most isocenters (5, p = 0.015) and venous drainage routes (3, p < 0.001), and the lowest peripheral dose (16.6 Gy, p = 0.011) and isodose level coverage (64.3%, p = 0.006). CSDAVFs presenting with ocular patterns were less likely to be completely obliterated (hazard ratio 0.531, p = 0.009). After adjustment for age, CSDAVFs with more venous drainage routes were less likely to be completely obliterated (hazard ratio 0.784, p = 0.039).
GKS is an equally effective treatment option for all 3 CSDAVF types. Furthermore, the number of venous drainage routes may help in predicting treatment outcomes and making therapeutic decisions.
Xin Zhang, Tamrakar Karuna, Zhi-Qiang Yao, Chuan-Zhi Duan, Xue-Min Wang, Shun-Ting Jiang, Xi-Feng Li, Jia-He Yin, Xu-Ying He, Shen-Quan Guo, Yun-Chang Chen, Wen-Chao Liu, Ran Li and Hai-Yan Fan
Among clinical and morphological criteria, hemodynamics is the main predictor of aneurysm growth and rupture. This study aimed to identify which hemodynamic parameter in the parent artery could independently predict the rupture of anterior communicating artery (ACoA) aneurysms by using multivariate logistic regression and two-piecewise linear regression models. An additional objective was to look for a more simplified and convenient alternative to the widely used computational fluid dynamics (CFD) techniques to detect wall shear stress (WSS) as a screening tool for predicting the risk of aneurysm rupture during the follow-up of patients who did not undergo embolization or surgery.
One hundred sixty-two patients harboring ACoA aneurysms (130 ruptured and 32 unruptured) confirmed by 3D digital subtraction angiography at three centers were selected for this study. Morphological and hemodynamic parameters were evaluated for significance with respect to aneurysm rupture. Local hemodynamic parameters were obtained by MR angiography and transcranial color-coded duplex sonography to calculate WSS magnitude. Multivariate logistic regression and a two-piecewise linear regression analysis were performed to identify which hemodynamic parameter independently characterizes the rupture status of ACoA aneurysms.
Univariate analysis showed that WSS (p < 0.001), circumferential wall tension (p = 0.005), age (p < 0.001), the angle between the A1 and A2 segments of the anterior cerebral artery (p < 0.001), size ratio (p = 0.023), aneurysm angle (p < 0.001), irregular shape (p = 0.005), and hypertension (grade II) (p = 0.006) were significant parameters. Multivariate analyses showed significant association between WSS in the parent artery and ACoA aneurysm rupture (p = 0.0001). WSS magnitude, evaluated by a two-piecewise linear regression model, was significantly correlated with the rupture of the ACoA aneurysm when the magnitude was higher than 12.3 dyne/cm2 (HR 7.2, 95% CI 1.5–33.6, p = 0.013).
WSS in the parent artery may be one of the reliable hemodynamic parameters characterizing the rupture status of ACoA aneurysms when the WSS magnitude is higher than 12.3 dyne/cm2. Analysis showed that with each additional unit of WSS (even with a 1-unit increase of WSS), there was a 6.2-fold increase in the risk of rupture for ACoA aneurysms.